﻿var numPoints = 20;
var centrePos = Vector3(0,0,12);
 var vortex : GameObject;
for (var pointNum = 0; pointNum < numPoints; pointNum++)
{
 
    // "i" now represents the progress around the circle from 0-1
    // we multiply by 1.0 to ensure we get a fraction as a result.
    var i = (pointNum * 1.0) / numPoints;
 
    // get the angle for this step (in radians, not degrees)
    var angle = i * Mathf.PI * 2;
 
    // the X & Y position for this angle are calculated using Sin & Cos
    var x = Mathf.Sin(angle) * 5;
    var y = Mathf.Cos(angle) * 5;
 
   var pos = Vector3(x, y, 0) + centrePos;
 
    // no need to assign the instance to a variable unless you're using it afterwards:
    Instantiate (vortex, pos, Quaternion.identity);
    vortex.rigidbody.AddRelativeForce(Vector3.forward, 200);
 
}     